Unit Overviews

There are roughly 15 units for each race, which isn’t a lot, but most resources assume that you know what all of them do and how they’re used. I’ll leave the full explanation to Liquipedia (which I highly recommend), but here’s my less than 2 sentence version for each:

Terran

SCV – basic worker

MULE – specialized workers. Use Orbital Command energy to get these super-fast miners, which are absolutely worth it

Marine – basic infantry unit. They’re a little flimsy, but with Stimpack and Combat Shields and in large numbers, they can deal a lot of damage to air and ground units

Marauder – heavy infantry. Use their bonus damage against Stalkers, Siege Tanks, Roaches, and other armored units, but note that they can’t shoot up

Reaper – harass infantry unit. Scout and harass in the first few minutes of the game

Hellion – fast raider car. Sneak them into your opponents base to kill workers or just kill Zerglings on the map

Hellbat – transformed Hellion tank. Drop them in your opponent’s mineral lines or put them in front of your army against Zealots and Zerglings

Widow Mine – recharging mine. Burrow in critical positions to fire off missiles periodically at workers and clumps of units

Siege Tank – a tank. Siege them in battles to do massive splash damage at long range.

Thor – massive mechanical unit. Use as anti-air in mech armies and to tank more damage for your Siege Tanks.

Viking – transformable flying unit. Long range air-to-air attack while flying to kill Overlords, Brood Lords, Medivacs, Void Rays, Colossi, and more, but they can also land to fight on the ground as well

Medivac – flying healing transport. Drop units in your opponent’s base or just keep them with infantry armies to heal them

Banshee – flying cloakable harassment. They can only attack ground units, but they do a lot of damage and are very annoying to mineral lines.